Synergistic enhancement of thermal conductivity and solar-thermal conversion in phase change composites via polydopamine-modified silicon carbide and copper nanosheets

This study reports a novel strategy to fabricate phase change composites (PCCs) by integrating polydopamine (PDA)-modified ultrafine silicon carbide (SiC) with copper nanosheets (CuNSs) in paraffin wax (PW). The PDA coating (10–20 nm) on SiC forms a conjugated aromatic layer for enhanced solar-light absorption, while two-dimensional CuNSs construct a continuous thermal-conductive network.” The results show that the thermal conductivity of the optimized PCCs reaches 3.9 W m −1  K −1 (16.3-fold improvement over pure PW), and the solar-thermal conversion efficiency achieves 88.9 % due to the synergistic effect of PDA's light absorption and CuNSs' localized surface plasmon resonance. Additionally, the mass retention rate of PCCs at 80 °C is 99.5 %, demonstrating excellent shape stability. This work provides a multi-functional strategy for improving energy storage performance, holding potential for applications in solar-integrated building systems and thermal management.